Abstract: A powdered medicament-mixed gas injecting apparatus includes a first passage having a gas supply opening at one end thereof for supplying gas. A second passage includes a container-fitting end portion at one end thereof for fitting thereto a container opening of a powdered medicament container in which powdered medicament is accommodated. One end is closed and the other end is provided with the container opening. The other end of the second passage is coupled with the other end of the first passage. The second passage serves for introducing supply gas fed from the gas supply opening of the first passage to the powdered medicament container, and for introducing powdered medicament-mixed gas which has been formed by mixing the supply gas with the powdered medicament in a direction opposite to a direction in which the supply gas is fed. The second passage allows gas to pass bidirectionally therethrough.